Normal flora are helpful when they are .
a. within tissues
b. on body surfaces
c. in the blood
d. excreted
e. able to combat MRSA

Normal flora are helpful when they are within tissues

Explanation:

Normal flora are organisms that are naturally found especially within tissues they include bacteria which are natural flora of such habitat

humans are now responsible for causing changes in the environment that hurt animals and plant species. we take up more space on earth for our homes and cities. we pollute habitats. human activity often changes or destroys the habitats that plants and animals need to survive.